How do sharks sense electricity?

Each visible pore leads into a canal filled with conductive gel. At the canal’s base, specialized receptor cells respond to tiny voltage differences between the pore and the shark’s body. Hundreds or thousands of canals create a spatial array around the head. The brain can compare their activity and use the pattern to orient toward a signal.

Living animals generate weak electric fields whenever muscles contract and nerves fire. A buried flatfish may be visually hidden, yet its respiratory movements still create a changing signal. Experiments that remove or alter sensory cues show that sharks combine smell, water movement, vision and electroreception rather than relying on a single magic sense from start to finish.

Laboratory and field studies show sensitivity to extremely small electric-field fluctuations. That does not translate into unlimited range: electric fields from small animals diminish steeply with distance. Electroreception is best understood as a precise final-approach system, particularly valuable in turbid water, under sand or at night.

Because a conductor moving through Earth’s magnetic field can induce voltage, scientists have long asked whether ampullae also support magnetic orientation. Sharks clearly respond to magnetic stimuli in experiments, but the exact receptor and neural mechanism remain active research topics. “May help navigation” is a stronger statement than claiming a complete built-in GPS.